A historic or an historic event.

From what I can find out on the net, either is correct. "An historic event' has always been my choice because it sounds better to my ear and looks better on paper.
To my ear, the "H" in Historic seems to be a vowel sound so I use "An." Following that logic I'd use An with "An hysterical event" but it doesn't sound right. Maybe I need to
repeat it over and over a few times. What am I missing here?

I'm working on a tale based on "An historical event" right now and the usage of "A" or "An" popped up.

Whether the leading h is silent is locale-dependent. The choice of a vs an is based on whether the word begins with a consonant sound, not whether the initial letter is customarily defined as a consonant.